NEW YORK – Scorpion Therapeutics on Tuesday said it began treating patients in a Phase I/II trial of its PI3Kα inhibitor STX-478 in hormone receptor (HR)-positive, HER2-negative breast cancer and other solid tumors.
Scorpion is initially enrolling patients with HR-positive, HER2-negative advanced breast cancer in the dose-escalation portion of the study. Once a dosage is established, the firm will open the trial to other cohorts including to patients with gynecologic, head and neck, and solid tumors harboring a PI3Kα mutation. Researchers will evaluate STX-478 as a monotherapy and combined with estrogen receptor antagonist fulvestrant.
The firm expects to report initial safety, pharmacokinetic, pharmacodynamic, and preliminary efficacy data from the Phase I portion of the study in 2024.
"STX-478 is a wild-type-sparing, [central nervous system]-penetrant, oral inhibitor of mutant PI3Kα with excellent preclinical pharmacokinetic properties," Michael Streit, chief medical officer of Scorpion, said in a statement. "In this Phase I/II trial, we will aim to demonstrate how these important traits translate into a potentially superior product profile that offers a wider therapeutic window and greater efficacy."
Scorpion, based in Boston, initially launched in October 2020, and STX-478 is its first program to enter clinical studies. This month, Scorpion entered into a licensing agreement with Pierre Fabre to develop two of Scorpion's drugs, STX-721 and STX-241, for EGFR-mutated non-small cell lung cancer. Last year, the firm also partnered with AstraZeneca to develop drugs against transcription factors, which are proteins that play a key role in controlling gene expression and regulating cell growth and survival.